I would instead fly into Munich.
Munich, then Austria, then Switzerland, then France all by trainb... fly to copenhagen, train to Stockhom, fly to Lapland then fly to Turkey.
Generally, short train hops work best. You move and train in the morning, get to your hotel by 2 or so and can go do something and stretch your legs in the afternoon.
So something like this ...
fly to Munich.
5 nights Munich
It sounds like a lot but you will be jetlagged. plenty to do, take it slow and enjoy it.
4 nights Salzburg
(munich to Salzburg <2 hrs)
Austria in winter is spectacular. Vienna is a long day trip, but doable if you really want.
3 nights Innsbruck
(Salzburg - Innsbruck <2 hrs)
Mountains, scenery, winter and snow ... so amazing. (I put this in as Munich-Vienna-Salzburg is pretty log hops and doesnt work as well. and Salzburg to Lucerne is 6.5 hrs which is too long with little kids. Keeping the trips shorter means you will enjoy what you see so much more)
4 nights Lucerne
(innsbruck - Lucerne = 4.5 hrs)
Lucerne is a great base to get around Switzerland. the trains are fabulous and Lucerne is pretty central. that train trip is pretty amazing too.
2 nights in Lyon
(Lucerne - Lyon 5.5 hrs)
Is there a special reason for Lyon? If not I would skip it and go direct to Paris. Paris is only 4.5 hrs as fast trains and direct routes ... and then either do day trips from Paris into champagne/Loire valley or chartres etc.
7 nights in Paris
Lyon - Paris is 2hrs
fly Paris - Denmark
4 nights Copenhagen
3 nights Stockholm
Copenhagen - Stockhom is 5.5 hrs
overnight ferry - stockholm to Helsinki
3 nights helsinki
fly to Rovanemi
5 nights rovanemi
fly to Istanbul
5 nights Istanbul/Turkey
cutting out the 2 nights in Lyon - that is 46 nights.
If it were me, I would think carefully about Copenhagen. I have included Stockholm and Helsinki because they fit with your itinerary and otherwise you are spending basically a day flying to Copenhagen, spending a few nights there and then another day flying to Finland. Better to actually spend a while there and see something.
But if it were me, I would spend more time in Germany/france/switzerland ... even Italy - and fly from France to Rovanemi and then to Istanbul.